Semi-flash steam-boiler.



C. A. SAWTBLLE. SEMI-FLASH STEAM BDILBR.

APPLIATION FILED NOV. 20,'1912A 1,085,634. Patented Feb. 3, 1914.

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` APPLICATION FILED NOV. 20. 1912. 1,085,634 Patented Feb. 3, 1914..

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TED STATES PATENT DEFI@ CHARLES A. SAWTELLE, 0F DAYTON, OHIO, ASS-IGNOR OF ONE-FOURTH T0 JAMES SAUNDERS, ONE-FOURTH. T0 EDWARD L. MCCLEARY, AND ONE-FOURTH TO ELWOOD C. BAVER, ALL OF DAYTON, OHIO.

SEMI-FLASH STEAM-BOILER.

nosaesa.

To all whom it may concern Be it known that I, CHARLES A. SAW- TELLE, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented a new and useful Improvement in Semi-Flash Steam-Boilers, of which the following is a sp ecication.

This invention relates to new and useful improvements in the semi-flash type of steam boilers. j

The primary object of my invention is to provide a boiler of the semi-flash type in which the secondary bank of semi-liash tubes are supplied with fluid Jfrom the primary bank of semi-flash tubes; and also to provide means for constantly maintaining the fluid in said primaryV bank of semi-flash tubes at a. level equal to approximately halt their depth.

Another important obj ect of my invention is to provide means for delivering the saturated steam formed in said semi-flash tubes to the superheating tubes, practically free from moisture.

Vith the above and other incidental objects in view, my invention consists in the construction and arrangement of parts described in the following specification and set forth in the subjoined claims.

In the accompanying drawings, Figure 1 is a sectional elevation of my improved type of steam boiler. Fig. 2 is a sectional elevation of the fluid supply tank and float chamber. Fig. 3 is a sectional view of the boiler taken on the line b-b of Fig. 1. And Fig. 4 is a sectional view of the float chamber taken on the line a-a of Fig. 2.

Throughout the specilication and drawings, similar reerence characters denote corresponding parts.

In a detailed description of my invention, 1 designates the ash pit and 2 the lire box of a steam boiler. Suitably mounted upon the lire box 2 is a primary bank of semi-flash tubes 3 which enter a header 4 at the front of the boiler, see Fig. 1. VAlso entering the header 4 is a secondary bank of semi-flash tubes 5 disposed in staggered relation immediately above the semi-Hash tubes 3 and communicating therewith through the said header 4.

Above the secondary bank of'semi-tlash tubes 5 are mounted banks ot transverse Specication of Letters Patent.

Patented Feb. 3, 1914.

Application led November 20, 1912. Serial No. 732,413.

superheating tubes 6, these tubes communieating with each other through returnbends 7. The uppermost bank of tubes G are connected by elbows 8 to vertical tubes or risers 9, which communicate, through elbows 10, with the upper or secondary bank of semi-flash tubes 5. The lowermost bank of superheating tubes @communicates with a header 11 from which a conducting pipev 12 leads.

The lower or primary bank of semi-flash tubes 3 communicates with a float chamber 13. Depending from the top of the float chamber 13 is a bracket 14 to which is pivoted one end of a lever 15, to the other end of which is secured a ball-shaped float 16 preferably constructed of glass. Suitably cast in the top plate of the float chamber 13 is a downwardly projecting boss 17 and an upwardly extending boss 18. The boss 17 receives a cylinder 19 in which reciprocates the upper portion of a check valve 20, said valve being connected, by a link 21, to the lever 15. The bottom portion of the check valve 2O seats tightly against the lower end of the cylinder 19 when the oat 16 is elevated.I and when lowered the bottom portion of said valve is unseated to permit liquid to flow into the chamber 13 from above.

Mounted immediately above the float chamber 13 is a supply tank 22 which receives, through a. pipe 23, fluid at a pressure equal to or higher than that maintained in the boiler. The supply tank 22 communicates with the float chamber 13 through a vertical tube 24, the lower end of which is received by the boss 18. The upper end of the tube 24 projects through a screen 25 through which the incoming fluid must pass before entering the said tube 24. The incoming fluid often contains much foreign matter such as grease, rust, etc. which the screen 25 will intercept and prevent from entering the tube 24. This foreign matter is taken o, from time to time, through a drain pipe 2G. During the draining operation the screen 25 will be cleansed by the water above in its downward movement. The tank 22 communicates with the outlet pipe 12 through an equalizing pipe 27.

One side or' the float chamber 13 is provided with bosses 28 corresponding in number to the semi-flash tubes 3. Each of the bosses 28 is so constructed as to form a shoulder portion 29. Each boss is also threaded to receive a threaded gland 30 which tightens packing 31. The other side of the packing 81 vbears against a. split collar 32 which rests in a groove formed in the tube 3. lVhen the iioat chamber 13 is under pressure, the tubes 3 may be forced outwardly a short distance. It will now be seen that when the tubes are so moved, the collars 32 carried thereby will bear against the packing 3l. The glands 30, which are stationary in the bosses 28, will form a barrier for said packing and thus permit it to be compressed sufliciently by the outwardly moving collars 32 to prevent leakage at any time. This construction also permits an unequal expansion and contraction of the tubes 3.

. In operation, fluid enters the supply tank 22 through the pipe 23. After passing the level of the top of the pipe 24, the Huid will ficw therethrough into the ilo-at chamber 13 until the fluid in said chamber reaches a depth sufficient to raise the float 16 to a position to close the check valve 20. This valve is timed to be closed by the float when the fluid reaches a level in the floatchamber that insures the fluid filling the primary bank of semi-flush tubes 8 to approximately halt' their depth. This float construction therefore insures this depth of fluid being constantly maintained in the semi-flash tubes 3. As indicated by the arrows in Fig. 1, when the water in the semi-flash tubes 3 is heated sul'liciently, wet steam will pass through the header 4: into the secondary bank of semiflash tubes 5 where it is dried and superheated. From there it passes into the vertical tubes o-r risers 9, and in its upward movement therethrough is practically relieved of moisture, due to the fact that the risers 9 are of suflicient area and height to i'educe the velocity of the steam and permit gravity to separate moisture therefrom. The dry steam now passes into the uppermost bank ot super-heating tubes 6, and thence downwardly through the lower banks of said tubes, being completely converted into a gaseous state at high temperature. In such condition the stem enters the header 11 to be conveyed to its destination by the outlet pipe 12.

'I do not wish to be limited to the details of construction and arrangement herein shown and described, and any changes may said secondary bank of semi-flash tubes for superheating said steam, and means disposed between said secondary bank of semi-Hash tubes and the upper bank of said superheating tubes for relieving saidV steam of moisture, substantially as described.

2. In a semi-flash steam boiler, a primaryV bank of semi-flash tubes, means Afor constantly maintaining fluid in said tubes at a level equal to approximately half their depth, means for converting said fluid into saturated steam, a secondary bank of semiflash tubes communicating with and mounted above said rst named bank for receiving said steam in its saturated condition, a series of transverse tubes mounted above said semiflash tubes for superheating said steam, and risers disposed between said secondary bank of semi-flash tubes and said superheating tubes for relieving said steam of moisture, substantially as described.

3. In a semi-flash steam boiler, a primary bank of horizontal semi-flash tubes, fluid contained in said tubes, a fire box disposed immediately undern said primary bank ot semi-flash tubes for converting said lluid into wet steam, a secondary bank of horizontal semi-flash tubes mounted above said first named bank, the said secondary bank of tubes communicating with said primary bank through a header, to receive therefrom wet steam, a series of transverse tubes mounted above said semi-flash tubes for superheating and drying said steam, and

vertical tubes connecting said secondary bank of semi-flash tubes 'with the upper bank of said superheating tubes, substantially as described.

In testimony whereof I have hereunto set my hand this 16th day of November, 1912.

CHARLES A. SAWTELLE. Witnesses: Y

BYRON B. HABLAN, HOWARD S. SMITH.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents.Y

Washington, D. C. 

